From 474a3df9984347cb87c00780fa4a8ddc527353ef Mon Sep 17 00:00:00 2001
From: Austin Liu <193228693+Dingding-leo@users.noreply.github.com>
Date: Tue, 28 Jul 2026 05:55:59 +0930
Subject: [PATCH] fix(bedrock): preserve additionalModelRequestFields in
 converse payload (fixes #8746) (#8764)

Passes through request.additionalModelRequestFields in openAIToBedrockConverse so reasoning/thinking options passed from Kiro/Bedrock translators are retained in the AWS Converse payload.
---
 open-sse/executors/bedrock.ts       |  4 ++++
 tests/unit/executor-bedrock.test.ts | 13 +++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/open-sse/executors/bedrock.ts b/open-sse/executors/bedrock.ts
index 740e3e8bd5..200962af96 100644
--- a/open-sse/executors/bedrock.ts
+++ b/open-sse/executors/bedrock.ts
@@ -366,6 +366,10 @@ export function openAIToBedrockConverse(model, body) {
   const toolConfig = toolConfigFromOpenAI(request.tools, request.tool_choice);
   if (toolConfig) payload.toolConfig = toolConfig;
 
+  if (request.additionalModelRequestFields !== undefined) {
+    payload.additionalModelRequestFields = request.additionalModelRequestFields;
+  }
+
   return payload;
 }
 
diff --git a/tests/unit/executor-bedrock.test.ts b/tests/unit/executor-bedrock.test.ts
index 14fa822378..61f5b64d54 100644
--- a/tests/unit/executor-bedrock.test.ts
+++ b/tests/unit/executor-bedrock.test.ts
@@ -97,6 +97,19 @@ test("openAIToBedrockConverse avoids duplicate Bedrock toolUse ids from mixed to
   assert.equal(payload.messages[2].content[0].toolResult.toolUseId, "call_dup");
 });
 
+test("openAIToBedrockConverse preserves additionalModelRequestFields", () => {
+  const payload = openAIToBedrockConverse("anthropic.claude-3-7-sonnet-20250219-v1:0", {
+    messages: [{ role: "user", content: "Hello" }],
+    additionalModelRequestFields: {
+      thinking: { type: "enabled", budget_tokens: 2048 },
+    },
+  });
+
+  assert.deepStrictEqual(payload.additionalModelRequestFields, {
+    thinking: { type: "enabled", budget_tokens: 2048 },
+  });
+});
+
 test("openAIToBedrockConverse drops duplicate pending tool call ids", () => {
   const payload = openAIToBedrockConverse("anthropic.claude-sonnet-4-6", {
     messages: [